Abstract: This invention is an apparatus and process for culturing aquatic animals. The apparatus comprises a container suitable for retaining water; a plurality of platforms vertically spaced from each other located in said container, the platforms being substantially parallel to each other and being designed to allow water to circulate therethrough while at the same time allowing solid food particles when dropped into the platform area to pass therethrough; and a feeding station placed on each of the platforms in a manner so that each feeding station is vertically and horizontally spaced from each adjacent station, has a structure such that the solid food particles are retained on the feeding station, and is substantially the same area as the adjacent feeding station.

Abstract: This invention is a screening apparatus for retaining small marine animals in a growing container connected to closed-loop aquaculture system. The screening apparatus comprises (a) a first plate; (b) a second plate about the same size as the first plate and substantially parallel to and spaced from the first plate; (c) a conduit passing through a centrally-located aperture in the first plate, the end of the conduit being attached to a face of the second plate, the corresponding edges of said plates being about the same distance from the outer wall of the conduit; (d) a fluid permeable material extending between the edges of said plates and enclosing said conduit by being snugly fitted at least around the periphery of the first plate; (e) the conduit having apertures around its circumference; and (f) a pump means for transferring a fluid through the conduit. The screening device is particularly useful in a closed-loop aquaculture system which includes a biological filter means.

Abstract: This invention is drawn to the use of an open-cell, polyurethane foam to remove dissolved contaminants from water in an aquaculture system. The foam is made by suitably reacting a hydroxylated ether with a diisocyanate. The foam filter is particularly useful in a water purification system which is a combination of a biological filter, a protein skimmer, and the polyurethane foam filter and such a combination forms the basis of a closed-loop aquaculture system. A process for removing dissolved contaminants in an aquaculture system is disclosed along with a process for growing aquatic animals in a system using the polyurethane foam filter.